Stacked reel multipliers

ABSTRACT

A slot game may assign a multiplier value to a stacked reel having an outcome including a stack of special symbols or wild symbols. The assigned multiplier value may be selected based on a random game outcome of preceding reels. The slot game may display the stacked reel with the assigned multiplier value or by replacing the stack of special symbols with a single symbol and the assigned multiplier value. The slot game may display a merged multiplier value over adjacent stacked reels, the merged multiplier value being the product of the assigned multiplier values for each of the adjacent stacked reels.

CLAIM OF PRIORITY

This application is a Continuation of U.S. application Ser. No.17/449,588, filed Sep. 30, 2021, which claims the benefit of priority ofU.S. Provisional Application 63/203,847, filed Aug. 2, 2021, both ofwhich are herein incorporated by reference in their entirety.

BACKGROUND

Electronic gaming machines (“EGMs”) or gaming devices provide a varietyof wagering games such as slot games, video poker games, video blackjackgames, roulette games, video bingo games, keno games and other types ofgames that are frequently offered at casinos and other locations. Playon EGMs typically involves a player establishing a credit balance byinputting money, or another form of monetary credit, and placing amonetary wager (from the credit balance) on one or more outcomes of aninstance (or single play) of a primary or base game. In some cases, aplayer may qualify for a special mode of the base game, a secondarygame, or a bonus round of the base game by attaining a certain winningcombination or triggering event in, or related to, the base game, orafter the player is randomly awarded the special mode, secondary game,or bonus round. In the special mode, secondary game, or bonus round, theplayer is given an opportunity to win extra game credits, game tokens orother forms of payout. In the case of “game credits” that are awardedduring play, the game credits are typically added to a credit metertotal on the EGM and can be provided to the player upon completion of agaming session or when the player wants to “cash out.”

“Slot” type games are often displayed to the player in the form ofvarious symbols arrayed in a row-by-column grid or matrix. Specificmatching combinations of symbols along predetermined paths (or paylines)through the matrix indicate the outcome of the game. The displaytypically highlights winning combinations/outcomes for identification bythe player. Matching combinations and their corresponding awards areusually shown in a “pay-table” which is available to the player forreference. Often, the player may vary his/her wager to include differingnumbers of paylines and/or the amount bet on each line. By varying thewager, the player may sometimes alter the frequency or number of winningcombinations, frequency or number of secondary games, and/or the amountawarded.

Typical games use a random number generator (RNG) to randomly determinethe outcome of each game. The game is designed to return a certainpercentage of the amount wagered back to the player over the course ofmany plays or instances of the game, which is generally referred to asreturn to player (RTP). The RTP and randomness of the RNG ensure thefairness of the games and are highly regulated. Upon initiation of play,the RNG randomly determines a game outcome and symbols are then selectedwhich correspond to that outcome. Notably, some games may include anelement of skill on the part of the player and are therefore notentirely random.

SUMMARY

Some embodiments provide a gaming device, a method, and a gaming systemthat assigns a multiplier to a stack of special symbols and in someembodiments replaces the stack of special symbols with a single symboland the multiplier. In some embodiments the multiplier is assigned basedon the number of preceding stacked reels based on random outcomes. Insome embodiments, the multiplier is randomly assigned. In someembodiments adjacent multipliers are merged into a single multiplierthat is a product of the assigned multipliers. In some embodiments thenumber of special symbols available to each reel depends on the reelposition, such that one or more later reel strips have fewer availablespecial symbols than one or more earlier reel strips.

A first embodiment provides a gaming system that includes a displaysystem and a game controller including one or more processors. The gamecontroller executing instructions which cause the game controller torandomly determine, using a random number generator, display symbols fora first reel, the display symbols selected from a first symbol setincluding one or more special symbols. Executing the instructionsfurther causes the game controller to randomly determine, using a randomnumber generator, display symbols for at least one subsequent reel, thedisplay symbols selected from a second symbol set including a pluralityof special symbols. Executing the instructions further causes the gamecontroller to determine whether the display symbols of the subsequentreel comprise a stack of special symbols, such that the subsequent reelis a stacked reel. If the subsequent reel is a stacked reel, the gamecontroller advances a stack counter to track a count of precedingstacked reels, assigns a multiplier value based on the count ofpreceding stacked reels, and controls the display system to display theassigned multiplier for the stacked reel.

Another embodiment provides a gaming system including a user interfacesystem, a display system including one or more displays, and a controlsystem including one or more processors. The user interface isconfigured for receiving an indication to initiate one or more instancesof a slot game. The control system executes instructions which cause thecontrol system to perform operations that include randomly selecting,with a random number generator, display symbols for a first reel, thedisplay symbols selected from a first symbol set including one or morespecial symbols. Executing the instructions further causes the controlsystem to randomly select, with a random number generator, displaysymbols for a second reel, the display symbols selected from a secondsymbol set including a plurality of special symbols. Executing theinstructions further causes the control system to randomly select, witha random number generator, display symbols for a third reel, the displaysymbols selected from a third symbol set including a plurality ofspecial symbols. Executing the instructions further causes the controlssystem to assign a first multiplier value to the second reel based onthe second reel being the first stacked reel if the second reel is astacked reel, such that the randomly selected display symbols form astack of special symbols, and if the second reel is part of a wincombination. Executing the instructions further causes the controlsystem to assign a second multiplier value to the third reel based onthe third reel being the second stacked reel if the third reel is astacked reel and part of a win combination. Executing the instructionsfurther causes the control system to control the display system todisplay outcomes of the first, second, and third reels and the assignedmultiplier value over the corresponding reel of each stacked reel.

Another embodiment provides one or more machine-readable devices storinginstructions. When the instructions are executed by one or moreprocessors, they cause performance of operations including randomlydetermining, using a random number generator, an outcome for each reelof a plurality of reels, each outcome including display symbols selectedfrom a reel strip that includes a plurality of special symbols. Theinstructions when executed further cause performance of operationsincluding determining that the outcome of at least one reel of theplurality of reels includes a stack of special symbols, such that the atleast one reel is a stacked reel. The instructions when executed furthercause performance of operations including (if the stacked reel is partof a win combination) assigning a multiplier value to the stacked reelusing a stack counter and a lookup table, such that the assignedmultiplier value is based on the number of preceding stacked reels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary diagram showing several EGMs networked withvarious gaming related servers.

FIG. 2A is a block diagram showing various functional elements of anexemplary EGM.

FIG. 2B depicts a casino gaming environment according to one example.

FIG. 2C is a diagram that shows examples of components of a system forproviding online gaming according to some aspects of the presentdisclosure.

FIG. 3 illustrates, in block diagram form, an implementation of a gameprocessing architecture algorithm that implements a game processingpipeline for the play of a game in accordance with variousimplementations described herein.

FIG. 4A is a flowchart illustrating an example method of displaying reelmultiplier values for stacked reels based on the random game outcome ofthe preceding reel(s).

FIG. 4B is a flowchart illustrating an example method of assigning reelmultiplier values for stacked reels based on the random game outcome ofthe preceding reel(s).

FIG. 5 is an example screen display showing an outcome for the firstreel that includes at least one special symbol.

FIG. 6 is the example screen display of FIG. 5 showing an outcome forthe second reel which has landed a stack of special symbols.

FIG. 7 is the example screen display of FIG. 6 showing the stack ofspecial symbols of the second reel replaced with a single symbol and amultiplier.

FIG. 8 is the example screen display of FIG. 7 showing an outcome forthe third reel which has landed a stack of special symbols.

FIG. 9 is the example screen display of FIG. 8 showing the stack ofspecial symbols of the third reel replaced with a single symbol and amultiplier.

FIG. 10 is the example screen display of FIG. 9 showing the multipliersof the second and third reels merged into a single multiplier.

FIG. 11 is the example screen display of FIG. 10 showing an outcome forthe fourth reel which has landed a stack of special symbols.

FIG. 12 is the example screen display of FIG. 11 showing the stack ofspecial symbols of the fourth reel replaced with a single symbol, and amerged multiplier for the second, third, and fourth reels.

FIG. 13 is the example screen display of FIG. 12 showing an outcome forthe fifth reel which has landed a stack of special symbols.

FIG. 14 is the example screen display of FIG. 13 showing the stack ofspecial symbols of the fifth reel replaced with a single symbol andshowing a merged multiplier for the second, third, fourth, and fifthreels.

FIGS. 15 and 16 are example screen displays showing non-consecutivestacks of dynamic reels replaced with a single symbol and a multiplier.

FIG. 17 is an example screen display showing randomly assignedmultipliers for reels with stacks of special symbols.

DETAILED DESCRIPTION

A first aspect of the present disclosure is generally directed toassigning different multiplier values to stacked reels based on therandom outcome of preceding reels. The set of reels includes a number ofspecial symbols, which are symbols that can contribute to a “wincombination” (i.e., pay path). In some examples, the special symbols arestackable (in some examples the special symbols are only stackable forcertain reels of the reel grid). A stacked reel (i.e., a reel that isfully populated by the special symbols, or in some cases wild symbols)that is part of a “win combination” based on the outcome of the reels ofthe reel grid is treated as a single symbol with an assigned multiplier.In some examples, the assigned multiplier is determined based on thenumber of preceding stacked reels and a predetermined sequence ofmultipliers. In some examples, the assigned multiplier is determinedbased on a random multiplier, determined using a random number generatorand a lookup table. The pay evaluation of a “win combination” includes aproduct of the assigned multipliers. In some examples, adjacentmultipliers are displayed as merged such that a single multiplierrepresents multiple stacked reels (i.e., the single multiplier is theproduct of the adjacent multipliers). In some examples, the specialsymbols are dynamic symbols such that the set of reels includes a numberof dynamic symbols, and for a given spin a selected special symbol ischosen to replace all of the dynamic symbols.

In terms of technical effects, the gaming device achieves a designatedgame volatility and RTP that complies with regulation for a game featurethat assigns a multiplier value when a symbol stack lands on a reel. Incontrast to conventional game features that assign multiplier values toa symbol, the present gaming devices, methods, and systems increase themultiplier value based on a determination whether the same stack landedon previous reels. By doing so, a game could apply a relatively largemultiplier value to the winning award. As an example, the reel thatlands a first stack receives a 5× multiplier, a second stack receives a6× multiplier, a third stack receives a 7× multiplier, and a fourthstack receives an 8× multiplier the game could potentially generate a1680× multiplier. Thus, without proper balancing, increasing themultiplier value for each subsequent reel stack could greatly increasethe potential payout that violates regulatory requirements. To balancethe RTP and comply with regulations, one or more later reel strips mayhave fewer available special symbols than one or more earlier reels,such that landing a stack of the special symbols is more likely for theone or more earlier reels than for the one or more later reels. Forexample, reels 2 and 3 may have more available special symbols thanreels 4 and 5. In the case of randomly assigned multipliers for stackedreels, the RTP can be balanced by using weighted lookup tables, or byusing different lookup tables for different reels to determine themultiplier.

The gaming system also improves computer usability and enhances theplayer's understanding and experience. For example, by displaying asingle symbol with a multiplier in place of a stack of symbols, thegaming system helps the player to better understand the outcome of thereel and its potential effect on the payout. Further, by displayingadjacent stacked reels with a merged multiplier representing the productof the assigned multiplier for each reel, the gaming system helps theplayer easily understand the combined effect of the reel outcomes. In asense, the gaming system is optimizing the display of paylines byproviding the benefits of a stacked reel while simplifying the conceptfor the player such that the player does not need to understand how tocalculate a payout based on a stacked reel but can instead instantly seethe value of that stacked reel in the form of the displayed multiplier.As such, the gaming system also changes the way a player builds equityin the game (by assigning multipliers to stacked reels) while alsomaking it easier for the player to understand how to build that equity.Displaying the stacked symbols as a single symbol, assigning amultiplier value to the reel based on the number of preceding stackedreels (which result from random outcomes), and merging multipliers ofstacked reels represents new EGM functionality not previouslyimplemented that provides another approach to presenting how a gamingdevice builds equity in a game, improves the usability of the gamingdevice, and enhances a player's understandability of obtaining certaingame outcomes.

In some examples, various described features may be implemented as partof a base game, a bonus game, a feature game, or a combination of these.

FIG. 1 illustrates several different models of EGMs which may benetworked to various gaming related servers. Shown is a system 100 in agaming environment including one or more server computers 102 (e.g.,slot servers of a casino) that are in communication, via acommunications network, with one or more gaming devices 104A-104X (EGMs,slots, video poker, bingo machines, etc.) that can implement one or moreaspects of the present disclosure. The gaming devices 104A-104X mayalternatively be portable and/or remote gaming devices such as, but notlimited to, a smart phone, a tablet, a laptop, or a game console. Gamingdevices 104A-104X utilize specialized software and/or hardware to formnon-generic, particular machines or apparatuses that comply withregulatory requirements regarding devices used for wagering or games ofchance that provide monetary awards.

Communication between the gaming devices 104A-104X and the servercomputers 102, and among the gaming devices 104A-104X, may be direct orindirect using one or more communication protocols. As an example,gaming devices 104A-104X and the server computers 102 can communicateover one or more communication networks, such as over the Internetthrough a web site maintained by a computer on a remote server or overan online data network including commercial online service providers,Internet service providers, private networks (e.g., local area networksand enterprise networks), and the like (e.g., wide area networks). Thecommunication networks could allow gaming devices 104A-104X tocommunicate with one another and/or the server computers 102 using avariety of communication-based technologies, such as radio frequency(RF) (e.g., wireless fidelity (WiFi®) and Bluetooth®), cable TV,satellite links and the like.

In some implementation, server computers 102 may not be necessary and/orpreferred. For example, in one or more implementations, a stand-alonegaming device such as gaming device 104A, gaming device 104B or any ofthe other gaming devices 104C-104X can implement one or more aspects ofthe present disclosure. However, it is typical to find multiple EGMsconnected to networks implemented with one or more of the differentserver computers 102 described herein.

The server computers 102 may include a central determination gamingsystem server 106, a ticket-in-ticket-out (TITO) system server 108, aplayer tracking system server 110, a progressive system server 112,and/or a casino management system server 114. Gaming devices 104A-104Xmay include features to enable operation of any or all servers for useby the player and/or operator (e.g., the casino, resort, gamingestablishment, tavern, pub, etc.). For example, game outcomes may begenerated on a central determination gaming system server 106 and thentransmitted over the network to any of a group of remote terminals orremote gaming devices 104A-104X that utilize the game outcomes anddisplay the results to the players.

Gaming device 104A is often of a cabinet construction which may bealigned in rows or banks of similar devices for placement and operationon a casino floor. The gaming device 104A often includes a main doorwhich provides access to the interior of the cabinet. Gaming device 104Atypically includes a button area or button deck 120 accessible by aplayer that is configured with input switches or buttons 122, an accesschannel for a bill validator 124, and/or an access channel for aticket-out printer 126.

In FIG. 1 , gaming device 104A is shown as a Relm XL™ model gamingdevice manufactured by Aristocrat® Technologies, Inc. As shown, gamingdevice 104A is a reel machine having a gaming display area 118comprising a number (typically 3 or 5) of mechanical reels 130 withvarious symbols displayed on them. The mechanical reels 130 areindependently spun and stopped to show a set of symbols within thegaming display area 118 which may be used to determine an outcome to thegame.

In many configurations, the gaming device 104A may have a main display128 (e.g., video display monitor) mounted to, or above, the gamingdisplay area 118. The main display 128 can be a high-resolution liquidcrystal display (LCD), plasma, light emitting diode (LED), or organiclight emitting diode (OLED) panel which may be flat or curved as shown,a cathode ray tube, or other conventional electronically controlledvideo monitor.

In some implementations, the bill validator 124 may also function as a“ticket-in” reader that allows the player to use a casino issued creditticket to load credits onto the gaming device 104A (e.g., in a cashlessticket (“TITO”) system). In such cashless implementations, the gamingdevice 104A may also include a “ticket-out” printer 126 for outputting acredit ticket when a “cash out” button is pressed. Cashless TITO systemsare used to generate and track unique bar-codes or other indicatorsprinted on tickets to allow players to avoid the use of bills and coinsby loading credits using a ticket reader and cashing out credits using aticket-out printer 126 on the gaming device 104A. The gaming device 104Acan have hardware meters for purposes including ensuring regulatorycompliance and monitoring the player credit balance. In addition, therecan be additional meters that record the total amount of money wageredon the gaming device, total amount of money deposited, total amount ofmoney withdrawn, total amount of winnings on gaming device 104A.

In some implementations, a player tracking card reader 144, atransceiver for wireless communication with a mobile device (e.g., aplayer's smartphone), a keypad 146, and/or an illuminated display 148for reading, receiving, entering, and/or displaying player trackinginformation is provided in gaming device 104A. In such implementations,a game controller within the gaming device 104A can communicate with theplayer tracking system server 110 to send and receive player trackinginformation.

Gaming device 104A may also include a bonus topper wheel 134. When bonusplay is triggered (e.g., by a player achieving a particular outcome orset of outcomes in the primary game), bonus topper wheel 134 isoperative to spin and stop with indicator arrow 136 indicating theoutcome of the bonus game. Bonus topper wheel 134 is typically used toplay a bonus game, but it could also be incorporated into play of thebase or primary game.

A candle 138 may be mounted on the top of gaming device 104A and may beactivated by a player (e.g., using a switch or one of buttons 122) toindicate to operations staff that gaming device 104A has experienced amalfunction or the player requires service. The candle 138 is also oftenused to indicate a jackpot has been won and to alert staff that a handpayout of an award may be needed.

There may also be one or more information panels 152 which may be aback-lit, silkscreened glass panel with lettering to indicate generalgame information including, for example, a game denomination (e.g.,$0.25 or $1), pay lines, pay tables, and/or various game relatedgraphics. In some implementations, the information panel(s) 152 may beimplemented as an additional video display.

Gaming devices 104A have traditionally also included a handle 132typically mounted to the side of main cabinet 116 which may be used toinitiate game play.

Many or all the above described components can be controlled bycircuitry (e.g., a game controller) housed inside the main cabinet 116of the gaming device 104A, the details of which are shown in FIG. 2A.

An alternative example gaming device 104B illustrated in FIG. 1 is theArc™ model gaming device manufactured by Aristocrat™ Technologies, Inc.Note that where possible, reference numerals identifying similarfeatures of the gaming device 104A implementation are also identified inthe gaming device 104B implementation using the same reference numbers.Gaming device 104B does not include physical reels and instead showsgame play functions on main display 128. An optional topper screen 140may be used as a secondary game display for bonus play, to show gamefeatures or attraction activities while a game is not in play, or anyother information or media desired by the game designer or operator. Insome implementations, the optional topper screen 140 may also oralternatively be used to display progressive jackpot prizes available toa player during play of gaming device 104B.

Example gaming device 104B includes a main cabinet 116 including a maindoor which opens to provide access to the interior of the gaming device104B. The main or service door is typically used by service personnel torefill the ticket-out printer 126 and collect bills and tickets insertedinto the bill validator 124. The main or service door may also beaccessed to reset the machine, verify and/or upgrade the software, andfor general maintenance operations.

Another example gaming device 104C shown is the Helix™ model gamingdevice manufactured by Aristocrat® Technologies, Inc. Gaming device 104Cincludes a main display 128A that is in a landscape orientation.Although not illustrated by the front view provided, the main display128A may have a curvature radius from top to bottom, or alternativelyfrom side to side. In some implementations, main display 128A is a flatpanel display. Main display 128A is typically used for primary game playwhile secondary display 128B is typically used for bonus game play, toshow game features or attraction activities while the game is not inplay or any other information or media desired by the game designer oroperator. In some implementations, example gaming device 104C may alsoinclude speakers 142 to output various audio such as game sound,background music, etc.

Many different types of games, including mechanical slot games, videoslot games, video poker, video black jack, video pachinko, keno, bingo,and lottery, may be provided with or implemented within the depictedgaming devices 104A-104C and other similar gaming devices.

Each gaming device may also be operable to provide many different games.Games may be differentiated according to themes, sounds, graphics, typeof game (e.g., slot game vs. card game vs. game with aspects of skill),denomination, number of paylines, maximum jackpot, progressive ornon-progressive, bonus games, and may be deployed for operation in Class2 or Class 3, etc.

FIG. 2A is a block diagram depicting exemplary internal electroniccomponents of a gaming device 200 connected to various external systems.All or parts of the gaming device 200 shown could be used to implementany one of the example gaming devices 104A-X depicted in FIG. 1 . Asshown in FIG. 2A, gaming device 200 includes a topper display 216 oranother form of a top box (e.g., a topper wheel, a topper screen, etc.)that sits above cabinet 218. Cabinet 218 or topper display 216 may alsohouse a number of other components which may be used to add features toa game being played on gaming device 200, including speakers 220, aticket printer 222 which prints bar-coded tickets or other media ormechanisms for storing or indicating a player's credit value, a ticketreader 224 which reads bar-coded tickets or other media or mechanismsfor storing or indicating a player's credit value, and a player trackinginterface 232. Player tracking interface 232 may include a keypad 226for entering information, a player tracking display 228 for displayinginformation (e.g., an illuminated or video display), a card reader 230for receiving data and/or communicating information to and from media ora device such as a smart phone enabling player tracking. FIG. 2 alsodepicts utilizing a ticket printer 222 to print tickets for a TITOsystem server 108. Gaming device 200 may further include a billvalidator 234, player-input buttons 236 for player input, cabinetsecurity sensors 238 to detect unauthorized opening of the cabinet 218,a primary game display 240, and a secondary game display 242, eachcoupled to and operable under the control of game controller 202.

The games available for play on the gaming device 200 are controlled bya game controller 202 that includes one or more processors 204.Processor 204 represents a general-purpose processor, a specializedprocessor intended to perform certain functional tasks, or a combinationthereof. As an example, processor 204 can be a central processing unit(CPU) that has one or more multi-core processing units and memorymediums (e.g., cache memory) that function as buffers and/or temporarystorage for data. Alternatively, processor 204 can be a specializedprocessor, such as an application specific integrated circuit (ASIC),graphics processing unit (GPU), field-programmable gate array (FPGA),digital signal processor (DSP), or another type of hardware accelerator.In another example, processor 204 is a system on chip (SoC) thatcombines and integrates one or more general-purpose processors and/orone or more specialized processors. Although FIG. 2A illustrates thatgame controller 202 includes a single processor 204, game controller 202is not limited to this representation and instead can include multipleprocessors 204 (e.g., two or more processors).

FIG. 2A illustrates that processor 204 is operatively coupled to memory208. Memory 208 is defined herein as including volatile and nonvolatilememory and other types of non-transitory data storage components.Volatile memory is memory that do not retain data values upon loss ofpower. Nonvolatile memory is memory that do retain data upon a loss ofpower. Examples of memory 208 include random access memory (RAM),read-only memory (ROM), hard disk drives, solid-state drives, universalserial bus (USB) flash drives, memory cards accessed via a memory cardreader, floppy disks accessed via an associated floppy disk drive,optical discs accessed via an optical disc drive, magnetic tapesaccessed via an appropriate tape drive, and/or other memory components,or a combination of any two or more of these memory components. Inaddition, examples of RAM include static random access memory (SRAM),dynamic random access memory (DRAM), magnetic random access memory(MRAM), and other such devices. Examples of ROM include a programmableread-only memory (PROM), an erasable programmable read-only memory(EPROM), an electrically erasable programmable read-only memory(EEPROM), or other like memory device. Even though FIG. 2A illustratesthat game controller 202 includes a single memory 208, game controller202 could include multiple memories 208 for storing program instructionsand/or data.

Memory 208 can store one or more game programs 206 that provide programinstructions and/or data for carrying out various implementations (e.g.,game mechanics) described herein. Stated another way, game program 206represents an executable program stored in any portion or component ofmemory 208. In one or more implementations, game program 206 is embodiedin the form of source code that includes human-readable statementswritten in a programming language or machine code that containsnumerical instructions recognizable by a suitable execution system, suchas a processor 204 in a game controller or other system. Examples ofexecutable programs include: (1) a compiled program that can betranslated into machine code in a format that can be loaded into arandom access portion of memory 208 and run by processor 204; (2) sourcecode that may be expressed in proper format such as object code that iscapable of being loaded into a random access portion of memory 208 andexecuted by processor 204; and (3) source code that may be interpretedby another executable program to generate instructions in a randomaccess portion of memory 208 to be executed by processor 204.

Alternatively, game programs 206 can be set up to generate one or moregame instances based on instructions and/or data that gaming device 200exchanges with one or more remote gaming devices, such as a centraldetermination gaming system server 106 (not shown in FIG. 2A but shownin FIG. 1 ). For purpose of this disclosure, the term “game instance”refers to a play or a round of a game that gaming device 200 presents(e.g., via a user interface (UI)) to a player. The game instance iscommunicated to gaming device 200 via the network 214 and then displayedon gaming device 200. For example, gaming device 200 may execute gameprogram 206 as video streaming software that allows the game to bedisplayed on gaming device 200. When a game is stored on gaming device200, it may be loaded from memory 208 (e.g., from a read only memory(ROM)) or from the central determination gaming system server 106 tomemory 208.

Gaming devices, such as gaming device 200, are highly regulated toensure fairness and, in many cases, gaming device 200 is operable toaward monetary awards (e.g., typically dispensed in the form of aredeemable voucher). Therefore, to satisfy security and regulatoryrequirements in a gaming environment, hardware and softwarearchitectures are implemented in gaming devices 200 that differsignificantly from those of general-purpose computers. Adapting generalpurpose computers to function as gaming devices 200 is not simple orstraightforward because of: (1) the regulatory requirements for gamingdevices 200, (2) the harsh environment in which gaming devices 200operate, (3) security requirements, (4) fault tolerance requirements,and (5) the requirement for additional special purpose componentryenabling functionality of an EGM. These differences require substantialengineering effort with respect to game design implementation, gamemechanics, hardware components, and software.

One regulatory requirement for games running on gaming device 200generally involves complying with a certain level of randomness.Typically, gaming jurisdictions mandate that gaming devices 200 satisfya minimum level of randomness without specifying how a gaming device 200should achieve this level of randomness. To comply, FIG. 2A illustratesthat gaming device 200 could include an RNG 212 that utilizes hardwareand/or software to generate RNG outcomes that lack any pattern. The RNGoperations are often specialized and non-generic in order to comply withregulatory and gaming requirements. For example, in a slot game, gameprogram 206 can initiate multiple RNG calls to RNG 212 to generate RNGoutcomes, where each RNG call and RNG outcome corresponds to an outcomefor a reel. In another example, gaming device 200 can be a Class IIgaming device where RNG 212 generates RNG outcomes for creating Bingocards. In one or more implementations, RNG 212 could be one of a set ofRNGs operating on gaming device 200. More generally, an output of theRNG 212 can be the basis on which game outcomes are determined by thegame controller 202. Game developers could vary the degree of truerandomness for each RNG (e.g., pseudorandom) and utilize specific RNGsdepending on game requirements. The output of the RNG 212 can include arandom number or pseudorandom number (either is generally referred to asa “random number”).

In FIG. 2A, RNG 212 and hardware RNG 244 are shown in dashed lines toillustrate that RNG 212, hardware RNG 244, or both can be included ingaming device 200. In one implementation, instead of including RNG 212,gaming device 200 could include a hardware RNG 244 that generates RNGoutcomes. Analogous to RNG 212, hardware RNG 244 performs specializedand non-generic operations in order to comply with regulatory and gamingrequirements. For example, because of regulation requirements, hardwareRNG 244 could be a random number generator that securely produces randomnumbers for cryptography use. The gaming device 200 then uses the securerandom numbers to generate game outcomes for one or more game features.In another implementation, the gaming device 200 could include bothhardware RNG 244 and RNG 212. RNG 212 may utilize the RNG outcomes fromhardware RNG 244 as one of many sources of entropy for generating securerandom numbers for the game features.

Another regulatory requirement for running games on gaming device 200includes ensuring a certain level of RTP. Similar to the randomnessrequirement discussed above, numerous gaming jurisdictions also mandatethat gaming device 200 provides a minimum level of RTP (e.g., RTP of atleast 75%). A game can use one or more lookup tables (also calledweighted tables) as part of a technical solution that satisfiesregulatory requirements for randomness and RTP. In particular, a lookuptable can integrate game features (e.g., trigger events for specialmodes or bonus games; newly introduced game elements such as extrareels, new symbols, or new cards; stop positions for dynamic gameelements such as spinning reels, spinning wheels, or shifting reels; orcard selections from a deck) with random numbers generated by one ormore RNGs, so as to achieve a given level of volatility for a targetlevel of RTP. (In general, volatility refers to the frequency orprobability of an event such as a special mode, payout, etc. Forexample, for a target level of RTP, a higher-volatility game may have alower payout most of the time with an occasional bonus having a veryhigh payout, while a lower-volatility game has a steadier payout withmore frequent bonuses of smaller amounts.) Configuring a lookup tablecan involve engineering decisions with respect to how RNG outcomes aremapped to game outcomes for a given game feature, while still satisfyingregulatory requirements for RTP. Configuring a lookup table can alsoinvolve engineering decisions about whether different game features arecombined in a given entry of the lookup table or split between differententries (for the respective game features), while still satisfyingregulatory requirements for RTP and allowing for varying levels of gamevolatility.

FIG. 2A illustrates that gaming device 200 includes an RNG conversionengine 210 that translates the RNG outcome from RNG 212 to a gameoutcome presented to a player. To meet a designated RTP, a gamedeveloper can set up the RNG conversion engine 210 to utilize one ormore lookup tables to translate the RNG outcome to a symbol element,stop position on a reel strip layout, and/or randomly chosen aspect of agame feature. As an example, the lookup tables can regulate a prizepayout amount for each RNG outcome and how often the gaming device 200pays out the prize payout amounts. The RNG conversion engine 210 couldutilize one lookup table to map the RNG outcome to a game outcomedisplayed to a player and a second lookup table as a pay table fordetermining the prize payout amount for each game outcome. The mappingbetween the RNG outcome to the game outcome controls the frequency inhitting certain prize payout amounts.

FIG. 2A also depicts that gaming device 200 is connected over network214 to player tracking system server 110. Player tracking system server110 may be, for example, an OASIS® system manufactured by Aristocrat®Technologies, Inc. Player tracking system server 110 is used to trackplay (e.g., amount wagered, games played, time of play and/or otherquantitative or qualitative measures) for individual players so that anoperator may reward players in a loyalty program. The player may use theplayer tracking interface 232 to access his/her account information,activate free play, and/or request various information. Player trackingor loyalty programs seek to reward players for their play and help buildbrand loyalty to the gaming establishment. The rewards typicallycorrespond to the player's level of patronage (e.g., to the player'splaying frequency and/or total amount of game plays at a given casino).Player tracking rewards may be complimentary and/or discounted meals,lodging, entertainment and/or additional play. Player trackinginformation may be combined with other information that is now readilyobtainable by a casino management system.

When a player wishes to play the gaming device 200, he/she can insertcash or a ticket voucher through a coin acceptor (not shown) or billvalidator 234 to establish a credit balance on the gaming device. Thecredit balance is used by the player to place wagers on instances of thegame and to receive credit awards based on the outcome of winninginstances. The credit balance is decreased by the amount of each wagerand increased upon a win. The player can add additional credits to thebalance at any time. The player may also optionally insert a loyaltyclub card into the card reader 230. During the game, the player viewswith one or more UIs, the game outcome on one or more of the primarygame display 240 and secondary game display 242. Other game and prizeinformation may also be displayed.

For each game instance, a player may make selections, which may affectplay of the game. For example, the player may vary the total amountwagered by selecting the amount bet per line and the number of linesplayed. In many games, the player is asked to initiate or select optionsduring course of game play (such as spinning a wheel to begin a bonusround or select various items during a feature game). The player maymake these selections using the player-input buttons 236, the primarygame display 240 which may be a touch screen, or using some other devicewhich enables a player to input information into the gaming device 200.

During certain game events, the gaming device 200 may display visual andauditory effects that can be perceived by the player. These effects addto the excitement of a game, which makes a player more likely to enjoythe playing experience. Auditory effects include various sounds that areprojected by the speakers 220. Visual effects include flashing lights,strobing lights or other patterns displayed from lights on the gamingdevice 200 or from lights behind the information panel 152 (FIG. 1 ).

When the player is done, he/she cashes out the credit balance (typicallyby pressing a cash out button to receive a ticket from the ticketprinter 222). The ticket may be “cashed-in” for money or inserted intoanother machine to establish a credit balance for play.

Additionally, or alternatively, gaming devices 104A-104X and 200 caninclude or be coupled to one or more wireless transmitters, receivers,and/or transceivers (not shown in FIGS. 1 and 2A) that communicate(e.g., Bluetooth® or other near-field communication technology) with oneor more mobile devices to perform a variety of wireless operations in acasino environment. Examples of wireless operations in a casinoenvironment include detecting the presence of mobile devices, performingcredit, points, comps, or other marketing or hard currency transfers,establishing wagering sessions, and/or providing a personalizedcasino-based experience using a mobile application. In oneimplementation, to perform these wireless operations, a wirelesstransmitter or transceiver initiates a secure wireless connectionbetween a gaming device 104A-104X and 200 and a mobile device. Afterestablishing a secure wireless connection between the gaming device104A-104X and 200 and the mobile device, the wireless transmitter ortransceiver does not send and/or receive application data to and/or fromthe mobile device. Rather, the mobile device communicates with gamingdevices 104A-104X and 200 using another wireless connection (e.g., WiFi®or cellular network). In another implementation, a wireless transceiverestablishes a secure connection to directly communicate with the mobiledevice. The mobile device and gaming device 104A-104X and 200 sends andreceives data utilizing the wireless transceiver instead of utilizing anexternal network. For example, the mobile device would perform digitalwallet transactions by directly communicating with the wirelesstransceiver. In one or more implementations, a wireless transmittercould broadcast data received by one or more mobile devices withoutestablishing a pairing connection with the mobile devices.

Although FIGS. 1 and 2A illustrate specific implementations of a gamingdevice (e.g., gaming devices 104A-104X and 200), the disclosure is notlimited to those implementations shown in FIGS. 1 and 2 . For example,not all gaming devices suitable for implementing implementations of thepresent disclosure necessarily include top wheels, top boxes,information panels, cashless ticket systems, and/or player trackingsystems. Further, some suitable gaming devices have only a single gamedisplay that includes only a mechanical set of reels and/or a videodisplay, while others are designed for bar counters or tabletops andhave displays that face upwards. Gaming devices 104A-104X and 200 mayalso include other processors that are not separately shown. Using FIG.2A as an example, gaming device 200 could include display controllers(not shown in FIG. 2A) configured to receive video input signals orinstructions to display images on game displays 240 and 242.Alternatively, such display controllers may be integrated into the gamecontroller 202. The use and discussion of FIGS. 1 and 2 are examples tofacilitate ease of description and explanation.

FIG. 2B depicts a casino gaming environment according to one example. Inthis example, the casino 251 includes banks 252 of EGMs 104. In thisexample, each bank 252 of EGMs 104 includes a corresponding gamingsignage system 254 (also shown in FIG. 2A). According to thisimplementation, the casino 251 also includes mobile gaming devices 256,which are also configured to present wagering games in this example. Themobile gaming devices 256 may, for example, include tablet devices,cellular phones, smart phones and/or other handheld devices. In thisexample, the mobile gaming devices 256 are configured for communicationwith one or more other devices in the casino 251, including but notlimited to one or more of the server computers 102, via wireless accesspoints 258.

According to some examples, the mobile gaming devices 256 may beconfigured for stand-alone determination of game outcomes. However, insome alternative implementations the mobile gaming devices 256 may beconfigured to receive game outcomes from another device, such as thecentral determination gaming system server 106, one of the EGMs 104,etc.

Some mobile gaming devices 256 may be configured to accept monetarycredits from a credit or debit card, via a wireless interface (e.g., viaa wireless payment app), via tickets, via a patron casino account, etc.However, some mobile gaming devices 256 may not be configured to acceptmonetary credits via a credit or debit card. Some mobile gaming devices256 may include a ticket reader and/or a ticket printer whereas somemobile gaming devices 256 may not, depending on the particularimplementation.

In some implementations, the casino 251 may include one or more kiosks260 that are configured to facilitate monetary transactions involvingthe mobile gaming devices 256, which may include cash out and/or cash intransactions. The kiosks 260 may be configured for wired and/or wirelesscommunication with the mobile gaming devices 256. The kiosks 260 may beconfigured to accept monetary credits from casino patrons 262 and/or todispense monetary credits to casino patrons 262 via cash, a credit ordebit card, via a wireless interface (e.g., via a wireless payment app),via tickets, etc. According to some examples, the kiosks 260 may beconfigured to accept monetary credits from a casino patron and toprovide a corresponding amount of monetary credits to a mobile gamingdevice 256 for wagering purposes, e.g., via a wireless link such as anear-field communications link. In some such examples, when a casinopatron 262 is ready to cash out, the casino patron 262 may select a cashout option provided by a mobile gaming device 256, which may include areal button or a virtual button (e.g., a button provided via a graphicaluser interface) in some instances. In some such examples, the mobilegaming device 256 may send a “cash out” signal to a kiosk 260 via awireless link in response to receiving a “cash out” indication from acasino patron. The kiosk 260 may provide monetary credits to the casinopatron 262 corresponding to the “cash out” signal, which may be in theform of cash, a credit ticket, a credit transmitted to a financialaccount corresponding to the casino patron, etc.

In some implementations, a cash-in process and/or a cash-out process maybe facilitated by the TITO system server 108. For example, the TITOsystem server 108 may control, or at least authorize, ticket-in andticket-out transactions that involve a mobile gaming device 256 and/or akiosk 260.

Some mobile gaming devices 256 may be configured for receiving and/ortransmitting player loyalty information. For example, some mobile gamingdevices 256 may be configured for wireless communication with the playertracking system server 110. Some mobile gaming devices 256 may beconfigured for receiving and/or transmitting player loyalty informationvia wireless communication with a patron's player loyalty card, apatron's smartphone, etc.

According to some implementations, a mobile gaming device 256 may beconfigured to provide safeguards that prevent the mobile gaming device256 from being used by an unauthorized person. For example, some mobilegaming devices 256 may include one or more biometric sensors and may beconfigured to receive input via the biometric sensor(s) to verify theidentity of an authorized patron. Some mobile gaming devices 256 may beconfigured to function only within a predetermined or configurable area,such as a casino gaming area.

FIG. 2C is a diagram that shows examples of components of a system forproviding online gaming according to some aspects of the presentdisclosure. As with other figures presented in this disclosure, thenumbers, types and arrangements of gaming devices shown in FIG. 2C aremerely shown by way of example. In this example, various gaming devices,including but not limited to end user devices (EUDs) 264 a, 264 b and264 c are capable of communication via one or more networks 417. Thenetworks 417 may, for example, include one or more cellular telephonenetworks, the Internet, etc. In this example, the EUDs 264 a and 264 bare mobile devices: according to this example the EUD 264 a is a tabletdevice and the EUD 264 b is a smart phone. In this implementation, theEUD 264 c is a laptop computer that is located within a residence 266 atthe time depicted in FIG. 2C. Accordingly, in this example the hardwareof EUDs is not specifically configured for online gaming, although eachEUD is configured with software for online gaming. For example, each EUDmay be configured with a web browser. Other implementations may includeother types of EUD, some of which may be specifically configured foronline gaming.

In this example, a gaming data center 276 includes various devices thatare configured to provide online wagering games via the networks 417.The gaming data center 276 is capable of communication with the networks417 via the gateway 272. In this example, switches 278 and routers 280are configured to provide network connectivity for devices of the gamingdata center 276, including storage devices 282 a, servers 284 a and oneor more workstations 570 a. The servers 284 a may, for example, beconfigured to provide access to a library of games for online game play.In some examples, code for executing at least some of the games mayinitially be stored on one or more of the storage devices 282 a. Thecode may be subsequently loaded onto a server 284 a after selection by aplayer via an EUD and communication of that selection from the EUD viathe networks 417. The server 284 a onto which code for the selected gamehas been loaded may provide the game according to selections made by aplayer and indicated via the player's EUD. In other examples, code forexecuting at least some of the games may initially be stored on one ormore of the servers 284 a. Although only one gaming data center 276 isshown in FIG. 2C, some implementations may include multiple gaming datacenters 276.

In this example, a financial institution data center 270 is alsoconfigured for communication via the networks 417. Here, the financialinstitution data center 270 includes servers 284 b, storage devices 282b, and one or more workstations 286 b. According to this example, thefinancial institution data center 270 is configured to maintainfinancial accounts, such as checking accounts, savings accounts, loanaccounts, etc. In some implementations one or more of the authorizedusers 274 a-274 c may maintain at least one financial account with thefinancial institution that is serviced via the financial institutiondata center 270.

According to some implementations, the gaming data center 276 may beconfigured to provide online wagering games in which money may be won orlost. According to some such implementations, one or more of the servers284 a may be configured to monitor player credit balances, which may beexpressed in game credits, in currency units, or in any otherappropriate manner. In some implementations, the server(s) 284 a may beconfigured to obtain financial credits from and/or provide financialcredits to one or more financial institutions, according to a player's“cash in” selections, wagering game results and a player's “cash out”instructions. According to some such implementations, the server(s) 284a may be configured to electronically credit or debit the account of aplayer that is maintained by a financial institution, e.g., an accountthat is maintained via the financial institution data center 270. Theserver(s) 284 a may, in some examples, be configured to maintain anaudit record of such transactions.

In some alternative implementations, the gaming data center 276 may beconfigured to provide online wagering games for which credits may not beexchanged for cash or the equivalent. In some such examples, players maypurchase game credits for online game play, but may not “cash out” formonetary credit after a gaming session. Moreover, although the financialinstitution data center 270 and the gaming data center 276 include theirown servers and storage devices in this example, in some examples thefinancial institution data center 270 and/or the gaming data center 276may use offsite “cloud-based” servers and/or storage devices. In somealternative examples, the financial institution data center 270 and/orthe gaming data center 276 may rely entirely on cloud-based servers.

One or more types of devices in the gaming data center 276 (orelsewhere) may be capable of executing middleware, e.g., for datamanagement and/or device communication. Authentication information,player tracking information, etc., including but not limited toinformation obtained by EUDs 264 and/or other information regardingauthorized users of EUDs 264 (including but not limited to theauthorized users 274 a-274 c), may be stored on storage devices 282and/or servers 284. Other game-related information and/or software, suchas information and/or software relating to leaderboards, playerscurrently playing a game, game themes, game-related promotions, gamecompetitions, etc., also may be stored on storage devices 282 and/orservers 284. In some implementations, some such game-related softwaremay be available as “apps” and may be downloadable (e.g., from thegaming data center 276) by authorized users.

In some examples, authorized users and/or entities (such asrepresentatives of gaming regulatory authorities) may obtaingaming-related information via the gaming data center 276. One or moreother devices (such EUDs 264 or devices of the gaming data center 276)may act as intermediaries for such data feeds. Such devices may, forexample, be capable of applying data filtering algorithms, executingdata summary and/or analysis software, etc. In some implementations,data filtering, summary and/or analysis software may be available as“apps” and downloadable by authorized users.

FIG. 3 illustrates, in block diagram form, an implementation of a gameprocessing architecture 300 that implements a game processing pipelinefor the play of a game in accordance with various implementationsdescribed herein. As shown in FIG. 3 , the gaming processing pipelinestarts with having a UI system 302 receive one or more player inputs forthe game instance. Based on the player input(s), the UI system 302generates and sends one or more RNG calls to a game processing backendsystem 314. Game processing backend system 314 then processes the RNGcalls with RNG engine 316 to generate one or more RNG outcomes. The RNGoutcomes are then sent to the RNG conversion engine 320 to generate oneor more game outcomes for the UI system 302 to display to a player. Thegame processing architecture 300 can implement the game processingpipeline using a gaming device, such as gaming devices 104A-104X and 200shown in FIGS. 1 and 2 , respectively. Alternatively, portions of thegaming processing architecture 300 can implement the game processingpipeline using a gaming device and one or more remote gaming devices,such as central determination gaming system server 106 shown in FIG. 1 .

The UI system 302 includes one or more UIs that a player can interactwith. The UI system 302 could include one or more game play UIs 304, oneor more bonus game play UIs 308, and one or more multiplayer UIs 312,where each UI type includes one or more mechanical UIs and/or graphicalUIs (GUIs). In other words, game play UI 304, bonus game play UI 308,and the multiplayer UI 312 may utilize a variety of UI elements, such asmechanical UI elements (e.g., physical “spin” button or mechanicalreels) and/or GUI elements (e.g., virtual reels shown on a video displayor a virtual button deck) to receive player inputs and/or present gameplay to a player. Using FIG. 3 as an example, the different UI elementsare shown as game play UI elements 306A-306N and bonus game play UIelements 310A-310N.

The game play UI 304 represents a UI that a player typically interfaceswith for a base game. During a game instance of a base game, the gameplay UI elements 306A-306N (e.g., GUI elements depicting one or morevirtual reels) are shown and/or made available to a user. In asubsequent game instance, the UI system 302 could transition out of thebase game to one or more bonus games. The bonus game play UI 308represents a UI that utilizes bonus game play UI elements 310A-310N fora player to interact with and/or view during a bonus game. In one ormore implementations, at least some of the game play UI element306A-306N are similar to the bonus game play UI elements 310A-310N. Inother implementations, the game play UI element 306A-306N can differfrom the bonus game play UI elements 310A-310N.

FIG. 3 also illustrates that UI system 302 could include a multiplayerUI 312 purposed for game play that differs or is separate from thetypical base game. For example, multiplayer UI 312 could be set up toreceive player inputs and/or presents game play information relating toa tournament mode. When a gaming device transitions from a primary gamemode that presents the base game to a tournament mode, a single gamingdevice is linked and synchronized to other gaming devices to generate atournament outcome. For example, multiple RNG engines 316 correspondingto each gaming device could be collectively linked to determine atournament outcome. To enhance a player's gaming experience, tournamentmode can modify and synchronize sound, music, reel spin speed, and/orother operations of the gaming devices according to the tournament gameplay. After tournament game play ends, operators can switch back thegaming device from tournament mode to a primary game mode to present thebase game. Although FIG. 3 does not explicitly depict that multiplayerUI 312 includes UI elements, multiplayer UI 312 could also include oneor more multiplayer UI elements.

Based on the player inputs, the UI system 302 could generate RNG callsto a game processing backend system 314. As an example, the UI system302 could use one or more application programming interfaces (APIs) togenerate the RNG calls. To process the RNG calls, the RNG engine 316could utilize gaming RNG 318 and/or non-gaming RNGs 319A-319N. GamingRNG 318 could corresponds to RNG 212 or hardware RNG 244 shown in FIG.2A. As previously discussed with reference to FIG. 2A, gaming RNG 318often performs specialized and non-generic operations that comply withregulatory and/or game requirements. For example, because of regulationrequirements, gaming RNG 318 could correspond to RNG 212 by being acryptographic RNG or pseudorandom number generator (PRNG) (e.g., FortunaPRNG) that securely produces random numbers for one or more gamefeatures. To securely generate random numbers, gaming RNG 318 couldcollect random data from various sources of entropy, such as from anoperating system (OS) and/or a hardware RNG (e.g., hardware RNG 244shown in FIG. 2A). Alternatively, non-gaming RNGs 319A-319N may not becryptographically secure and/or be computationally less expensive.Non-gaming RNGs 319A-319N can, thus, be used to generate outcomes fornon-gaming purposes. As an example, non-gaming RNGs 319A-319N cangenerate random numbers for generating random messages that appear onthe gaming device.

The RNG conversion engine 320 processes each RNG outcome from RNG engine316 and converts the RNG outcome to a UI outcome that is feedback to theUI system 302. With reference to FIG. 2A, RNG conversion engine 320corresponds to RNG conversion engine 210 used for game play. Aspreviously described, RNG conversion engine 320 translates the RNGoutcome from the RNG 212 to a game outcome presented to a player. RNGconversion engine 320 utilizes one or more lookup tables 322A-322N toregulate a prize payout amount for each RNG outcome and how often thegaming device pays out the derived prize payout amounts. In one example,the RNG conversion engine 320 could utilize one lookup table to map theRNG outcome to a game outcome displayed to a player and a second lookuptable as a pay table for determining the prize payout amount for eachgame outcome. In this example, the mapping between the RNG outcome andthe game outcome controls the frequency in hitting certain prize payoutamounts. Different lookup tables could be utilized depending on thedifferent game modes, for example, a base game versus a bonus game.

After generating the UI outcome, the game processing backend system 314sends the UI outcome to the UI system 302. Examples of UI outcomes aresymbols to display on a video reel or reel stops for a mechanical reel.In one example, if the UI outcome is for a base game, the UI system 302updates one or more game play UI elements 306A-306N, such as symbols,for the game play UI 304. In another example, if the UI outcome is for abonus game, the UI system could update one or more bonus game play UIelements 310A-310N (e.g., symbols) for the bonus game play UI 308. Inresponse to updating the appropriate UI, the player may subsequentlyprovide additional player inputs to initiate a subsequent game instancethat progresses through the game processing pipeline.

The example game processing architecture 300 shown in FIG. 3 can be usedto process game play instructions and generate outcomes as follows. Insome example implementations, the game processing architecture 300implements a game processing pipeline for a process (e.g. base reelgame, bonus reel game, feature reel game, etc.) that converts stackedreels that could contribute to a “win combination” to a single symbolspanning the reel and selects a multiplier based on the number ofpreceding stacked reels, merge assigned multipliers of adjacent reels,or the like. The UI system 302 (e.g., the game play UI 304 or bonus gameplay UI 308 of the UI system 302) causes the display system (e.g.display 240, 242) to display a single symbol in place of a stacked reeland a multiplier assigned based on the number of preceding stackedreels, a merged multiplier representing the product of assignedmultipliers of adjacent reels, or the like. For a play, the UI system302 (e.g., the game play UI 304 or bonus game play UI 308) makes one ormore RNG calls to the game processing backend system 314. In response,the backend system 314 performs various operations. For example, using agaming RNG 318, the RNG engine 316 generates one or more random numbers,which are passed to the RNG conversion engine 320. In variousembodiments, the RNG conversion engine 320, can use one or more of therandom number(s) and one or more of the lookup tables 322A . . . 322N,to determine a set of display symbols to populate the reels, to select aselected special symbol to substitute for dynamic symbols, or the like.After determining a game outcome, including combining the product ofassigned multipliers of stacked reels that are part of a “wincombination” (e.g. a payline etc.), or the like, the backend system 314performs a pay evaluation or otherwise determines results (e.g.,calculating whether any win conditions exist). The backend system 314returns generated result to the game play UI 304 or bonus game play UI308 of the UI system 302, which can among other operations controldisplay of the game outcome and results corresponding to the payevaluation. For example, the game play UI 304 or bonus game play UI 308in various embodiments may stop the spinning of reels at the displaysymbols determined for respective reel outcomes, replace stacked reels(fully populated with special symbols) with a single symbol and amultiplier assigned based on the number of preceding stacked reels,merge assigned multipliers for adjacent stacked reels to display asingle multiplier that is the product of the assigned multipliers,indicate win paths, or the like.

In general, the generated results returned by the backend system 314 caninclude game-related information (such as display symbols for therespective reels, outcomes) as well as animation effects not related togame parameters. Alternatively, the game play UI 304 (or bonus game playUI 308) can make one or more separate RNG calls to the backend system314 to determine animation effects. In response, the backend system 314can use the gaming RNG 318 and/or one or more of the non-gaming RNGs319A . . . 319N to generate random numbers, which the RNG conversionengine 320 uses (with one or more of the lookup tables 322A . . . 322N)to determine animation effects. The game play UI 304 (or bonus game playUI 308) can perform operations consistent with the animation effects,which are returned from the backend system 314.

FIG. 4A is a flowchart illustrating an example method 400 of displayingreel multiplier values for stacked reels based on the random gameoutcome of the preceding reel(s), for example, as may be presented ongaming device 200 of FIG. 2 using the procession architecture 300 ofFIG. 3 . Prior to the start of method 400, the gaming device 200 maybegin game play. For example, the gaming device 200 may establish anassociated credit value on a credit meter. For example, a player mayinsert a physical item having monetary value into a credit inputmechanism or device, such as the ticket reader 224 or bill validator 234of the gaming device 200 or otherwise establish a credit value. Inresponse to the received physical item, the gaming device 200 mayincrease a credit value based on the monetary value of the physicalitem. The gaming device 200 may then receive a wager. A player may useinput buttons 236 to specify a value of an amount to be wagered with thewager being funded by the credit value of the credit meter. The gamingdevice 200 may display a message such as “Press SPIN to play” on theprimary game display 240 or otherwise. When the player presses acorresponding SPIN button, for example via the player input buttons 236,the gaming device 200 may decrease the player's credit balance by thespecified wager and initiate play of a slot-type game. The method 400may be part of a base game, a secondary game, and/or a bonus game.

At 402, the game controller 202 controls the display system to displayan outcome for the first reel of the reel grid. The outcome for thefirst reel includes the display symbols that land on the first reel. Thefirst set of display symbols may be randomly selected from a reel strip,which includes at least one special symbol (i.e., a symbol which cancontribute to a “win combination” during a pay evaluation via ways payor one or more paylines). The special symbol can be any symbol, picture,image, number, letter, a combination of these, or the like.

At 404, the game controller 202 controls the display system to displayan outcome for a subsequent reel of the reel grid, for example a secondreel. The outcome for the subsequent reel (the “current reel” since itis the subsequent reel currently being addressed) includes the displaysymbols that land on the subsequent reel (e.g., the second reel). Thesecond set of display symbols may be randomly selected from a reelstrip, which includes a plurality of the special symbols. In variousexamples, each reel will use a different reel strip. In some examples,one or more reel strips may be used for multiple reels of the reelgrids.

At 406, the method 400 proceeds based on whether a win combination ispossible (or present) that includes the current reel (the currentsubsequent reel), that is, whether the special symbols (and/or wildsymbols in some examples) for multiple reels are positioned to allow fora “win combination” via the permitted pay paths (e.g., paylines or wayspay). In some examples, a “win combination” that includes the currentreel is possible (or present) if the current reel outcome and eachpreceding reel outcome includes at least one special symbol (and/or awild symbol) that is positioned to be connected by one or more paylinesor can contribute to All Ways pay (depending on the pay structure of thegame). For example, a “win combination” is still possible at the secondreel (that is when the second reel is the current reel/subsequent reel)if there is at least one special symbol in the first reel outcome and atleast one special symbol in the second reel outcome that can beconnected by a payline or contribute to All Ways pay (depending on thepay structure of the game). In some examples, a “win combination” ispresent if at least the first three reel outcomes include the specialsymbol (or a wild symbol in some examples), but only includes thecurrent reel if the current reel outcome and each preceding reel outcomeincludes the special symbol (or a wild symbol in some examples).

If a “win combination” including the current reel is not possible, themethod 400 proceeds to 412 and then proceeds based on whether there isan additional reel, that is, whether one or more reels remain in thereel grid for which an outcome has not yet been displayed. If there areone or more additional reels, the method 400 returns to 404 to displaythe outcome of a subsequent reel (e.g., a third reel after having justdisplayed the outcome of the second reel). In at least one example, thefirst reel and/or the second reel might not include any special symbols,or the special symbols of the first reel may not be positioned near thespecial symbols of the second reel, such that a “win combination” is notpossible, and the game controller 202 will control the display system todisplay the outcome for each subsequent reel until there are not anyremaining reels in the reel grid for which outcomes have not beendisplayed. When at 412 there are no additional reels in the reel gridfor which an outcome has not been displayed for the spin, the method 400proceeds to 414 at which the controller 202 controls the display systemto display the pay evaluation for the spin.

However, if at 406 a “win combination” including the current reel ispossible (for example because the current reel outcome and each of thepreceding reel outcomes includes a special symbol (or a wild symbol insome examples)) at 408 the method 400 proceeds based on whether thecurrent reel outcome (of the current “subsequent” reel) includes a stackof special symbols (and/or wild symbols in some examples). For example,in a 4×5 (row-by-column) reel grid, any single vertical reel thatincludes four of the special symbols (which may be the selected specialsymbols populating dynamic symbols) is fully populated by the specialsymbol and is considered to have a stack of the special symbols. In someexamples, symbols other than the special symbol may be stacked, but arenot be considered as a stack at 408 of the method 400. If the currentreel does not have a stack of the special symbols (which may includewild symbols in some examples), the method 400 proceeds to 414 andfurther proceeds based on whether there is an additional reel in thereel grid, as described above.

However, if at 408 the current reel (for the sake of example, the secondreel) includes a stack of the special symbols (and/or wild symbols insome examples), the method proceeds to 410, at which the game controller202 controls the display system to display an assigned multiplier valueto the current stacked reel. In some examples, the assigned multiplieris selected for the current stacked reel based on the number ofpreceding stacked reels that landed in the game outcome. In someexamples, the game controller 202 controls the display system to displaythe assigned multiplier over the current stack. In some examples, thegame controller 202 controls the display system to display the currentreel with the stack of special symbols (or wild symbols in someexamples) replaced with a single symbol (in some examples, the specialsymbol) and the assigned multiplier value. In some examples, thecontroller 202 controls the display system to display the assignedmultiplier near the current reel. In some examples, the controller 202controls the display system to display the assigned multiplier mergedwith adjacent assigned multipliers (e.g. the product of adjacentassigned multipliers for adjacent stacked reels is displayed as a singlemerged multiplier). In at least one example, the controller 202 controlsthe display system to display adjacent stacked reels merged as a singlereel with a single symbol and the merged multiplier. In some examples,the controller 202 only controls the display system to display mergedmultipliers after all of the reels of the reel grid land. In at leastone example, the controller 202 only displays an assigned reelmultiplier that is part of an already displayed win combination.

After the game controller 202 controls the display system to display theassigned multiplier of the current stacked reel, the method 400 proceedsto decision 412, and proceeds based on whether one or more additionalreels remains. As discussed above, if there are one or more additionalreels, the method 400 returns to step 404 and the game controller 202goes through steps 404-412 as appropriate for each additional(subsequent) reel. For example, in a 4×5 reel grid the method 400 willreturn to step 404 for the third reel, the fourth reel, and the fifthreel.

After the final reel, for example the fifth reel in a 4×5 reel grid, at414 the game controller 202 controls the display system to display thepay evaluation of the spin. In some examples, performing the payevaluation includes applying each reel that included a stack of specialsymbols (or in some examples, wild symbols) as a single symbol with theassigned multiplier. In some examples, the game controller 202 canfurther control the display system (at various points in method 400) todisplay reel anticipation while displaying outcomes of reels when asubsequent stack can contribute to a big win. For example, thecontroller 202 can control the display system to spin the subsequentreel for longer than normal, to shake an image, to highlight an image,or otherwise add graphics to draw attention to the subsequent reel andthe significance of the subsequent reel. For example, the gamecontroller 202 can control the display system to initiate reelanticipation for the fourth reel if the merged multiplier from theprevious stacks is 30×. In another example, the game controller 202 caninitiate reel anticipation for a reel if the previous reel has landed astack and another stack would result in a merged multiplier. In at leastone example, the game controller 202 can initiate reel anticipation fora fifth reel if the multiplier product from the previous stacks is 30×or more.

FIG. 4B is a flowchart illustrating an example method 450 of assigningreel multiplier values for stacked reels based on the random gameoutcome of the preceding reel(s), for example, as may be presented ongaming device 200 of FIG. 2 using the procession architecture 300 ofFIG. 3 . Prior to the start of method 450, the gaming device 200 maybegin game play. For example, the gaming device 200 may establish anassociated credit value on a credit meter. For example, a player mayinsert a physical item having monetary value into a credit inputmechanism or device, such as the ticket reader 224 or bill validator 234of the gaming device 200 or otherwise establish a credit value. Inresponse to the received physical item, the gaming device 200 mayincrease a credit value based on the monetary value of the physicalitem. The gaming device 200 may then receive a wager. A player may useinput buttons 236 to specify a value of an amount to be wagered with thewager being funded by the credit value of the credit meter. The gamingdevice 200 may display a message such as “Press SPIN to play” on theprimary game display 240 or otherwise. When the player presses acorresponding SPIN button, for example via the player input buttons 236,the gaming device 200 may decrease the player's credit balance by thespecified wager and initiate play of a slot-type game. The method 450may be part of a base game, a secondary game, and/or a bonus game.

In examples including dynamic symbols, at 452, the game controller 202selects one or more selected special symbols to replace the dynamicsymbols. The one or more special symbols may be selected randomly usinga random number generator, based on a sequence, based on a triggeringevent, or the like. In at least one example, the special symbol replacesall dynamic symbols. In other examples, the dynamic symbols may bereplaced by special symbols and other symbols (e.g., symbols that arenot special, symbols that do not contribute to a win combination,symbols that are not stackable, a combination of these or the like). Themethod 450 then proceeds to 454 (or in examples that do not includedynamic symbols, the method 450 begins at 454), at which the gamecontroller 202 determines outcomes for each of the reels of the reelgrid.

For example, the game controller 202 determines the first set of displaysymbols to populate the first reel for the first reel outcome. The firstset of display symbols may be selected from a full symbol set for thegame, such that the first set of display symbols is a subset of the fullsymbol set (i.e., a reel strip selected for the first reel). In someexamples the full symbol set will include both configurable andnon-configurable symbols. In an example, the configurable symbols mayinclude a common component and at least a variable component. Thevariable component may be, for example, indicative of a value of a prizethat is associated with each of the configurable symbols, for exampleeither an amount, or an indicator of a jackpot (Grand, Major, Mini, forexample), and/or may include a “wild” symbol, or a multiplier symbol(2×, 3×, etc.). The full symbol set (i.e., reel strip) includes one ormore special symbols which can contribute to a “win combination” duringa pay evaluation via ways pay or one or more paylines. The specialsymbol can be any symbol, picture, image, number, letter, a combinationof these, or the like. In some examples, the full symbol set (i.e., reelstrip) includes one or more dynamic symbols (configurable symbols) and asingle special symbol is selected to populate all dynamic symbols for agiven spin, instance, base game, feature game, bonus game, or the like.For example, a selected special symbol selected to populate dynamicsymbols for an instance will populate all dynamic symbols of all reeloutcomes for that instance with the selected special symbol. In at leastone example, the game controller 202 selects the selected special symbol(for populating the dynamic symbols) using the RNG engine 316. In someexamples, the game controller 202 selects the first set of displaysymbols from a subset of the full symbol set (i.e., the full symbol setmay include multiple reel strips and the game controller 202 uses one ofthe reel strips to select the display symbols for a given spin). Foreach spin, the game controller 202 will determine the first set ofdisplay symbols such that the first reel outcome may differ with eachspin. For example, the game controller 202 can select the first set ofdisplay symbols using the RNG engine 316.

The game controller 202 further determines a set of display symbols topopulate each subsequent reel of the reel grid. These sets of displaysymbols may also be selected from the full symbol set for the game orfrom subsets of the full symbol set (i.e., reel strips). In at least oneexample, the display symbols for each of the reels (including the firstreel) can be selected from the same reel strip. In some examples, thegame controller 202 may select the display symbols using different reelstrips for different reels. In some examples, the reel strips used forsubsequent reels include a plurality of special symbols which cancontribute to a “win combination” during a pay evaluation via All Wayspay or one or more paylines. In some examples, reel strips for thesubsequent reels include dynamic symbols (instead of special symbols)and the game controller 202 selects one or more selected special symbolsto populate the dynamic symbols (as described with reference to 452).The game controller 202 can select the display symbols for reel outcomesusing the RNG engine 316.

At 456, the game controller performs a pay evaluation based on therandom outcomes for the reels of the reel grid generated at 454. In atleast one example, performing the pay evaluation includes steps 458-466.At 458, the game controller 202 determines whether a “win combination”is present. That is, the game controller 202 determines whether thespecial symbols (and/or wild symbols in some examples) that wererandomly selected as display symbols for the reels of the reel grid arepositioned to allow for a “win combination” via the permitted pay paths(e.g., paylines or ways pay). If a “win combination” is not present, themethod 400 proceeds to step 466 at which the game controller 202controls the display system to display the outcome including each reeloutcome and the result of the pay evaluation.

However, if the game controller 202 determines that a “win combination”is present, for example because at least the first three reels of thereel grid include a special symbol (or wild symbol in some examples), at460 the game controller 202 determines whether a reel of the reel grid(that is part of a win combination) has landed a stack of specialsymbols (and/or wild symbols in some examples). For example, in a 4×5(row-by-column) reel grid, any single vertical reel outcome thatincludes four of the special symbols (which may be the selected specialsymbols populating dynamic symbols) is fully populated by the specialsymbol and is considered to have a stack of the special symbols. In someexamples, symbols other than the special symbol may be stacked, but maynot be considered a stack for purposes of 460. In some examples, onlycertain symbol types for the selected special symbols chosen to replacethe dynamic symbols will be considered a stack for purposes of 460.Thus, for some spins, the populated reel strips may contain no symboltypes that could trigger a stack for purposes of 460, even if they couldtrigger a stack of symbols other than special symbols and wild symbols.However, for ease of understanding, some examples referring to stackedsymbols, special symbols, dynamic symbols, or selected special symbolsassume symbols that count as a stack for purposes of 460. If the reeloutcomes of the reel grid do not include a stack of the special symbols(and/or wild symbols in some examples), the method 450 proceeds to step466 at which the game controller 202 controls the display system todisplay the outcome of the spin, including the at least one wincombination.

However, if the game controller 202 determines that outcomes of thereels of the reel grid include at least one stack of the special symbols(and/or wild symbols in some examples), the method proceeds to step 462,and the game controller 202 advances a stack counter that keeps track ofhow many reels have landed stacks of the special symbols (and/or wildsymbols in some examples). In some examples the counter may track thenumber of stacked reels for a given spin or instance. In other examplesthe counter may track the number of stacked reels over single ormultiple base games, feature games, bonus games, or the like. In someexamples, the stack counter tracks the number of preceding adjacentstacked reels (meaning an immediately preceding stacked reel that isadjacent to the current reel, and a stacked reel adjacent to thatstacked reel, and a stacked reel adjacent to that stacked reel, and soon and so forth, such that it only counts continuously adjacent stacksthat include a stacked reel adjacent to the current reel). In someexamples the stack counter tracks the number of preceding stacked reels,whether or not they are adjacent. In at least one example, the firstreel does not allow for stacked special symbols, such that the secondreel is the initial opportunity for the stack counter to count a stackedreel. For example, a reel grid having five reels can only have fourstacked reels (since the first reel cannot be a stacked reel). In atleast one example, the controller 202, advances the stack counter onestacked reel at a time in the order that the reel outcomes aredetermined or displayed. In at least one example, the controller 202advances the stack counter one stacked reel at a time from left toright.

At 464, the game controller 202 assigns a multiplier to each stackedreel based on the number of preceding stacked reels according to thestack counter. In some examples, the multiplier is based on the numberof preceding stacked reels that land in the same spin. In some examples,the multiplier is based on the number of adjacent preceding stackedreels that land in the same spin. In some examples, the multipliersincrease as the number of stacked reels that land for a given spinincrease. In some examples, the multipliers increase as the number ofadjacent stacked reels that land for a given spin increase. In at leastone example, the controller 202 uses a predefined sequence ofmultipliers. For example, the first stack is a 5× multiplier, the secondstack is a 5× multiplier, the third stack is a 7× multiplier, and thefourth stack is an 8× multiplier. In some examples, the adjacentsuccessive stacks receive an increased multiplier, but stacks that arenot adjacent to a preceding stack will not receive an increasedmultiplier. In such an example, if the second and fourth reels are theonly stacked reels, they may each be considered a “first stack” forpurposes of assigning a multiplier value since they are not adjacent,such that they would both be assigned the 5× multiplier. In anotherexample, if the second, fourth, and fifth reels land a stack of thespecial symbol, then the second and fourth reels are assigned the same6× multiplier and the fifth reel is assigned the 6× multiplier despite atotal of three stacked reels. In some examples, the controller 202 usesthe stack counter and a lookup table to determine what multiplier of thepredefined sequence corresponds to the stack number of each stackedreel.

In some examples the stacks need not be adjacent, so long as they arepart of a win combination. For example, if the first reel lands onespecial symbol, the second reel lands a stack of the special symbol(first stack), the third reel lands one special symbol, and the fourthreel lands a stack of the special symbol (second stack), then the secondreel will be assigned a 5× multiplier (since that is the multipliercorresponding to the first stack in the example), and the fourth reelwill be assigned a 6× multiplier (since that is the multipliercorresponding to the second stack in the example). In that example, thefirst stack (second reel) and the second stack (fourth reel) are notadjacent to one another, however they are connected by a special symbolvia the third reel, and the first reel includes a special symbol, suchthat both stacks are part of a “win combination”. In that same example,if the fifth reel also lands a stack of the special symbol, then itwould receive a 7× multiplier, since it is also part of a wincombination. Other examples may have different predefined sequences forassigning multipliers based on the stack number (or the number of stacksin preceding reels) of stacks that are part of a “win combination”.

In some examples, the multiplier can be randomly assigned, for exampleusing a lookup table and a random number generator. In such examples,the lookup table may be selected based on the number of precedingstacked reels (or their assigned multipliers) determined using the stackcounter. In some examples, different lookup tables may have differentpossible multipliers depending on the number of preceding stacked reels(or their assigned multipliers). For example, a lookup table for a laterstacked reel may include higher multipliers relative to a lookup tablefor an earlier stacked reel (particularly in examples where later reelstrips have fewer special symbols than earlier reels). In some examples,the lookup table may be a weighted lookup table, such that certainmultipliers have a greater chance of being randomly selected than othermultipliers. As another example, weighted tables for later stacked reelsmay be weighted such that higher multipliers are more likely than theyare for the weighted tables of the earlier stacked reels. In someexamples, the tables may be selected such that higher multipliers aremore likely for earlier stacked reels than later stacked reels.

After the game controller 202 assigns a reel multiplier to each stackedreel, the method 450 proceeds to 466, at which the game controller 202controls the display system to display the outcome of the spin,including the result of the pay evaluation based on any assignedmultiplier values. In some examples, the game controller 202 controlsthe display system to display the one or more stacks of special symbolsreplaced with a single special symbol with the assigned reel multiplier.For example, if the first reel lands at least one special symbol, andthe second reel lands a stack of four special symbols (such that thereel is fully populated with the special symbol), the stack of fourspecial symbols is replaced with a single image (which may be thespecial symbol) that extends for, or otherwise applies to, the entirereel. That is, the game controller 202, via the game processingarchitecture 300, controls the display system (for example primary gamedisplay 240 and secondary game display 242 of gaming device 200) toreplace the second reel having four special symbols with a reel having asingle symbol and the assigned multiplier. In other examples, the stackof special symbols is not replaced with a single symbol, but instead thegame controller 202 controls the display system to display the assignedmultiplier tagged to the stack of special symbols.

In at least one example, the game controller 202 controls the displaysystem to merge multipliers of adjacent stacks that are part of a “wincombination”. For example, if the first reel lands one or more specialsymbols, the second reel lands a stack of special symbols assigned a 5×multiplier, and the third reel lands a stack of special symbols assigneda 6× multiplier, since the second and third reels are adjacent stacks,the game controller 202 controls the display system to merge the 5× and6× multiplier to display a single 30× multiplier for the two reels(second and third). Each adjacent stack will be merged and increase themultiplier accordingly. In some examples, merged stacks, followed by areel with at least one special symbol but no stack of special symbols,followed by a subsequent stack of special symbols will result in thesubsequent stack of special symbols having the assigned multiplier asnormal, unmerged. In some examples, partial stacks of special symbolsare not replaced with a single symbol and/or assigned a multiplier. Insome examples, stacks of special symbols that cannot be part of a “wincombination” are not replaced with a single symbol and/or assigned amultiplier.

In some examples, different symbol sets and/or different reel stripsinclude different numbers of special symbols, such that achieving astack of special symbols is more likely in some reels than others. Forexample, earlier reel strips (e.g., reel strips used for the second reeland third reel) may include more special symbols while later reel strips(e.g., reel strips for the fourth reel and fifth reel) may include fewerspecial symbols. By doing so, the reel strips are constructed to make itharder to land a larger number of multiplier values for the spin (sincethe later reels are less likely to hit a stack of special symbols thanthe earlier reels), thereby offsetting increases in RTP.

By using dynamic symbols in some examples, the rate of symbol types thatprovide multiplier values (special symbols) can be controlled to obtaina desired RTP. Further, using dynamic symbols, rather than havingmultiple static stacks with different symbol types in a reel strip,prevents the occurrence of landing block symbol stacks (i.e., symbolstacks that prevent certain win combinations). Since assigning amultiplier is based on landing a stack of four special symbols (in theexample of four-high reels), this stack would inherently serve as amultiplier in a ways pay (All Ways) game, before the multiplier effectdescribed herein is applied. This existing multiplier effect of a stackoffsets a portion of the described assigned multiplier effect. As anexample, landing a full stack of four special symbols (in the example ofa four-high reel) is equivalent to a 4× multiplier (i.e., four differentways to achieve a payout in a ways pay (All Ways) game). Thus, assigninga 5× multiplier to the special symbol stack provides a slight increasein the pay relative to the pay that would have been received without theassigned multiplier effect. Landing two assigned multiplier values of 5×and 6× produces a 30× multiplier, while two stacks of four specialsymbols is conventionally equivalent to a 16× multiplier (e.g.,4××4×=16×). The described assigned multiplier values can start todeviate significantly as more assigned multiplier values are added tothe reel grid. However, this deviation can be controlled or offset basedon the number of special symbols (or dynamic symbols) included for eachreel strip. As such, the RTP can be balanced while providing the playerwith an opportunity to achieve higher multipliers.

In some examples, the stack counter can consider more than one type ofsymbol for stack purposes, or the special symbol can include more thanone symbol. For example, in addition to a special symbol that triggersthe multiplier effect, in some examples a wild symbol may serve the samepurpose as the special symbol such that it can contribute to a possible“win combination” (e.g., if the first reel does not land any of thespecial symbols but it does land a wild symbol, then a win is stillpossible based on the wild symbol), and a stacked reel of wild symbolswill count as a stacked reel for the stack counter and for assigningreel multipliers. For example, if the first reel lands a special symbol,the second reel lands a stack of wild symbols, and the third reel landsa stack of special symbols, in some examples the second reel (firststack) may receive a 5× multiplier and the third reel (second stack) mayreceive a 6× multiplier, even though the stacks are of different symbols(special symbol, wild symbol). Further, in some examples, adjacentstacks of wild symbols and special symbols have their multipliersmerged, such that in the previous example the multipliers of the secondand third reels would merge for a single 30× multiplier. Further, insome examples, the wild symbol stack is replaced by a single wild symbolthat extends the entire reel (e.g., 4-high for a 4-high reel). In someexamples, a reel that lands a combination of exclusively special symbolsand wild symbols is treated as a stack (or a stack of special symbols)for the purposes of the stack counter and assigning multipliers. Forexample, if a four-high reel includes three special symbols and threewild symbols, in some examples the reel would be considered a stackedreel for purposes of the stack counter and will be assigned a multiplierif it is part of a win combination. While specific examples ofmultipliers have been provided, any multiplier sequence or assignmentmay be used as long as the potential assigned multipliers are properlybalanced by the distribution of special symbols (or otherwise) toachieve a desired RTP. Further, while examples are described with regardto a 4×5 reel grid, the same methods, games, and systems could utilizereel grids of other dimensions.

FIG. 5 is an example screen display 500 showing a 4×5 reel grid thatincludes five reels 502, 504, 506, 508, 510 with four rows 512, 514,516, 518. The outcome for the first reel 502 includes two specialsymbols or selected special symbols 520 (selected special symbol beingthe symbol selected to substitute for dynamic symbols), such that in theillustrated example a “win combination” is still possible. While theillustrated example is based on a ways pay (All Ways), other examplesmay include any of a variety of games with any of a variety of rules forwhat constitutes a “win combination.” Further, while in the illustratedexample the remaining reels 504, 506, 508, 510 are blank, in otherexamples the gaming device 200 may display the remaining reels in any ofa variety of manners. For example, the reels could be continuouslyspinning, the reels could display a graphic that indicates they have notyet been spun, the reels could combine to form a single graphic, or thelike.

FIG. 6 is the example screen display 500 of FIG. 5 showing an outcomefor the second reel 504 which has landed a stack of special symbols 520.The first reel 502 and the second reel 504 outcomes include specialsymbols 520 in positions such that a “win combination” is possible. FIG.7 is the example screen display 500 of FIG. 6 showing the stack ofspecial symbols 520 of the second reel 504 outcome replaced with asingle symbol 702 and a multiplier 704. In the illustrated example, thesingle symbol 702 is a modified version of the special symbol 520, suchthat it is larger and visually applies to the entire 4-high reel. In atleast one example, the single symbol 702 or other graphical elements areapplied to the entire reel 504 to indicate that the reel represents thesingle symbol 702 with the multiplier 704. The multiplier 704 has beenselected as discussed above with reference to FIG. 4 , such that themultiplier 704 assigned to the second reel 504 (first stacked reel) is5×.

FIG. 8 is the example screen display 500 of FIG. 7 showing an outcomefor the third reel 506 which has landed a stack of special symbols 520.The first, second, and third reel outcomes 502, 504, 506 include dynamicsymbols 520 (or individual symbol 702) in positions such that a “wincombination” is possible. FIG. 9 is the example screen display 500 ofFIG. 8 showing the stack of special symbols 520 of the third reel 506replaced with a single symbol 704 and a multiplier 704. In theillustrated example, the multiplier 704 of the third reel 506 isdetermined based on a predetermined sequence of multipliers and thestack counter which indicates that there is one preceding stacked reel(second reel 504). As such, the third reel 506 has been assigned a 5×multiplier 704. FIG. 10 is the example screen display 500 of FIG. 9showing the multipliers 704 of the second and third reels 504, 506merged into a single multiplier 1002. In the illustrated example, sincethe first stack (second reel 504) and the second stack (third reel 506)are adjacent, their multipliers 704 are combined to display a single 30×multiplier (5×6=30). In some examples, the second adjacent stack (thirdreel 506) would never show the 6× multiplier as depicted in FIG. 9 butwould simply display the outcome including the stack of special symbols520 as depicted in FIG. 8 and then the merged multiplier 1002 asdepicted in FIG. 10 . In at least one example, instead of one singlesymbol 702 in each adjacent stacked reel (in the illustrated example,second and third reels 504, 506) the single symbol 702 is merged suchthat one single symbol 702 represents the adjacent stacked reels (in theillustrated example, second and third reels 504, 506), an example ofthis merged single symbol can be seen in FIG. 16 . In some examples,merged multipliers are not displayed until all of the reels land.

FIG. 11 is the example screen display 500 of FIG. 10 showing an outcomefor the fourth reel 508 which has landed a stack of special symbols 520.The first, second, third, and fourth reel outcomes 502, 504, 506, 508include special symbols 520 (or individual symbols 702) in positionssuch that a “win combination” is possible. FIG. 12 is the example screendisplay 500 of FIG. 11 showing the stack of special symbols 520 of thefourth reel 508 replaced with a single symbol 702, and a mergedmultiplier 1202 for the second, third, and fourth reels 504, 506, 508.In the illustrated example, the multiplier 704 (not shown) of the fourthreel 508 is determined based on a predetermined sequence of multipliersand the stack counter which indicates that there are two precedingstacked reels (second reel 504 and third reel 506). As such, the thirdstack (fourth reel 508) has been assigned a 7× multiplier 704 (notshown). In some examples, the game device 200 may first show the 7×assigned multiplier 704 before showing the merged multiplier 1202, butthat step has not been depicted here for the purpose of brevity. Themerged multiplier 1202 is the product of the multipliers 704 of thesecond, third, and fourth reels 504, 506, 508. In the illustratedexample, since the first stack (second reel 504), the second stack(third reel 506), and the third stack (fourth reel 508) are adjacent,their multipliers 704 are combined to display a single 210× mergedmultiplier 1202 (5×6×7=210). Or to put it another way, the 210× mergedmultiplier 1202 of FIG. 12 is the product of the 30× merged multiplier1102 of FIG. 11 and the 7× assigned multiplier 704 (not shown) of thethird stack (fourth reel 508) (30×7=210). As such, in some examples, thegame device 200 may first show the 7× assigned multiplier 704 for thethird stack (fourth reel 508) and then show it combined with the 30×merged multiplier 1102 (FIG. 11 ) of the first and second stacks (secondand third reels 504, 506) to produce the 210× merged multiplier 1202 ofFIG. 12 .

FIG. 13 is the example screen display 500 of FIG. 12 showing an outcomefor the fifth reel 510 which has landed a stack of special symbols 520.The first, second, third, fourth, and fifth reels 502, 504, 506, 508,510 include special symbols 520 (or individual symbols 702) in positionssuch that a “win combination” is possible. FIG. 14 is the example screendisplay 500 of FIG. 13 showing the stack of special symbols 520 of thefifth reel 510 replaced with a single symbol 702, and a mergedmultiplier 1402 for the second, third, fourth, and fifth reels 504, 506,508, 510. In the illustrated example, the multiplier 704 (not shown) ofthe fifth reel 510 is determined based on a predetermined sequence ofmultipliers and the stack counter which indicates that there are threepreceding stacked reels (second reel 504, third reel 506, and fourthreel 508). As such, the fourth stack (fifth reel 506) has been assignedan 8× multiplier 704 (not shown). In some examples, the game device 200may first show the 8× assigned multiplier 704 before showing the mergedmultiplier 1402, but that step has not been depicted here for thepurpose of brevity. The merged multiplier 1402 is the product of themultipliers 704 of the second, third, fourth, and fifth reels 504, 506,508, 510. In the illustrated example, since the first stack (second reel504), the second stack (third reel 506), the third stack (fourth reel508), and the fourth stack (fifth reel 510) are adjacent, theirmultipliers 704 are combined to display a single 1680× multiplier(5×6×7×8×=1680). Or to put it another way, the 1680× merged multiplier1402 of FIG. 14 is the product of the 210× merged multiplier 1202 ofFIG. 12 and the 8× assigned multiplier 704 (not shown) of the fourthstack (fifth reel 510) (210×8=1680). As such, in some examples, the gamedevice 200 may first show the 8× assigned multiplier 704 for the fourthstack (fifth reel 510) and then show it combined with the 210× mergedmultiplier 1202 (FIG. 12 ) of the first, second, and third stacks(second, third, and fourth reels 504, 506, 508) to produce the 1670×merged multiplier 1402 of FIG. 14 .

Conventionally, a stacked reel would be equivalent to a 4× multiplier,such that if the second, third, fourth, and fifth reels 504, 506, 508,510 were stacked reels (as in the example of FIG. 14 ) the conventionalscoring would be the equivalent of a 256× multiplier (4×4×4×4=256). Incontrast, the example of the present gaming devices, systems, andmethods depicted in FIG. 14 results in a 1680× multiplier, which is muchgreater than the 256× multiplier that results from conventional scoringof the same stacked reels. As such, the present gaming devices, systems,and methods allow for the possibility of much higher multipliers, whichas described above requires balancing to achieve a desired volatilityand RTP.

FIGS. 15 and 16 are example screen displays 1500, 1600 showingnon-consecutive stacks of dynamic reels replaced with a single symboland a multiplier. In the example of FIG. 15 , the second reel 504,fourth reel 508, and fifth reel 510 each included a stack of specialsymbols 520 (not shown) such that each was replaced with a single symbol702 and a multiplier 704. Even though the first stack (second reel 504)and the second stack (fourth reel 508) are not adjacent, in theillustrated example the assigned multiplier continues the sequence basedon the number of preceding stacks, such that the assigned multiplier 704for the second reel 504 (first stack) is 5× and the assigned multiplier704 for the fourth reel 508 (second stack) is 6×. In some examples, theassigned multipliers 704 for the second and third stacks (fourth andfifth reels 508, 510) would then be combined to create a mergedmultiplier of 42× since they are adjacent, while the assigned 5×multiplier of the non-adjacent first stack (second reel 504) wouldremain the same.

In other examples, only adjacent preceding stacks are included in thestack count. In such an example using the same multiplier sequence,since the fourth reel 508 does not have any adjacent preceding stacks(third reel 506 does not include a stack of special symbols 520, and thestack of the second reel 504 is not adjacent to the fourth reel 508),the stack of the fourth reel 508 would be treated as a first stack suchthat it would receive a 5× assigned multiplier. In such an example thestack of the second reel 504 would also be treated as a first stack andassigned a 5× multiplier, and the stack of the fifth reel 510 would betreated as a second stack and receive a 6× multiplier (such that thefourth and fifth reels 508, 510 would have a 30× merged multiplier).

In the example of FIG. 16 , the second reel 504, third reel 506, andfifth reel 510 each included a stack of special symbols 520 (not shown)such that each was replaced with a single symbol 702 and a multiplier704. In the illustrated example, since the first stack (second reel 504)and the second stack (third reel 506) are adjacent, their assignedmultipliers of 5× and 6× have been combined for a 30× merged multiplier1602, and the third stack (fifth reel 510) has been assigned a 7×multiplier 704 since it is not adjacent to any other stacks and it isthe third stack in the sequence. In the illustrated example, the secondand third reel 504, 506 are displayed with a shared single symbol 702and the merged multiplier 1602 such that they appear as one large reel.In other examples, the reels may not be fully merged (they are stilldistinct) but include the shared single symbol 702 and the mergedmultiplier 1602 as an overlay.

In an example that includes the same sequence of assigned multipliersbut only includes adjacent preceding stacks in the stack count, themultipliers for the second and third reels 504, 506 would still be 5×and 6×, respectively for a 30× merged multiplier 1602, but the fifthreel 510 would be assigned a 5× multiplier 704 as it would be treated asa first stack since there are not any preceding stacks adjacent to it(i.e., the fourth reel 508 does not include a stack).

FIG. 17 is an example screen display 1700 showing randomly assignedmultipliers 704 for reels with stacks of special symbols. Instead offollowing a sequence of multipliers based on the number of precedingstacks, the game device 200 uses a random number generator and one ormore lookup tables to assign a multiplier 704 to a stack. In theillustrated example, the first stack (second reel 504) has been randomlyassigned an 8× multiplier 704, the second stack (fourth reel 508) hasbeen randomly assigned a 7× multiplier 704, and the third stack (fifthreel 510) has been randomly assigned a 7× multiplier. In some examples,the multipliers 704 of adjacent stacks are still combined to create anddisplay a merged multiplier, such that the 5× multiplier 704 of thefourth reel 508 and the 7× multiplier 704 of the fifth reel 510 would becombined for a 35× merged multiplier. While the multipliers are randomlygenerated, the lookup tables can be selected to achieve a desiredvolatility and RTP. For example, a weighted lookup table can affect thelikelihood of a given multiplier being randomly selected. Further, notall available multipliers may be included on all lookup tables. In someexamples, one or more stacks may be assigned a multiplier based on asequence while one or more other stacks may be assigned a randomlygenerated multiplier.

While various examples use specific multipliers, specific sequences,etc., any multiplier or sequence may be used. Further, other examplesmay use different symbols, fonts, reel matrix sizes, display features, acombination of these, or the like.

Other non-limiting example configurations are described in the followingindividually numbered Examples.

Example 1 is a gaming system comprising: a display system; and a gamecontroller comprising one or more processors, the game controllerexecuting instructions which cause the game controller to: randomlydetermine, using a random number generator, display symbols for a firstreel, the display symbols selected from a first symbol set including oneor more special symbols; randomly determine, using a random numbergenerator, display symbols for at least one subsequent reel, the displaysymbols selected from a second symbol set including a plurality ofspecial symbols; determine whether the display symbols for thesubsequent reel comprise a stack of special symbols, such that thesubsequent reel is a stacked reel, and if the subsequent reel is astacked reel: advance a stack counter to track a count of precedingstacked reels; assign a multiplier value based on the count of precedingstacked reels; and control the display system to display the assignedmultiplier for the stacked reel.

In Example 2, the subject matter of Example 1 optionally includes thatthe first reel is an initial reel and determining outcomes for at leastone subsequent reel further comprises: determining outcomes for a secondreel and a third reel.

In Example 3, the subject matter of Example 2 optionally includes thatdetermining outcomes for the second reel and the third reel furthercomprises: determining that the second reel includes a stack of specialsymbols; assigning a first multiplier value to the second reel;determining that the third reel includes a stack of special symbols; andassigning a second multiplier value to the third reel.

In Example 4, the subject matter of Example 3 optionally includes thatthe instructions further cause the game controller to: control thedisplay system to merge the first multiplier value and the secondmultiplier value to display a merged multiplier value equal to theproduct of the first and second multiplier values.

In Example 5, the subject matter of any one or more of Examples 1-4optionally include that the instructions further cause the gamecontroller to: control the display system to merge adjacent reelmultiplier values of adjacent stacked reels to display a single mergedmultiplier value equal to the product of the adjacent multiplier values.

In Example 6, the subject matter of Example 5 optionally includes thatthe instructions further cause the game controller to: control thedisplay system to display the single merged multiplier value such thatit extends over the adjacent stacked reels corresponding to the adjacentmultiplier values.

In Example 7, the subject matter of any one or more of Examples 1-6optionally include that: the first symbol set includes one or moredynamic symbols; the second symbol set includes a plurality of dynamicsymbols; and the instructions further cause the game controller torandomly select, using a random number generator (RNG), a selectedspecial symbol to substitute for dynamic symbols of the first and secondsymbol sets, such that the selected special symbol is the one or morespecial symbols of the first symbol set and the plurality of specialsymbols of the second symbol set.

In Example 8, the subject matter of any one or more of Examples 1-7optionally include that advancing a stack counter to track a count ofpreceding stacked reels comprises: counting stacks of wild symbols andstacks of special symbols toward the count of preceding stacked reels.

In Example 9, the subject matter of any one or more of Examples 1-8optionally include that advancing a stack counter to track a count ofpreceding stacked reels comprises: counting only the immediatelypreceding adjacent stacked reel and any stacked reels adjacent to theimmediately preceding adjacent stacked reel toward the count ofpreceding stacked reels.

In Example 10, the subject matter of any one or more of Examples 1-9optionally include that assigning a multiplier value based on the countof preceding stacked reels comprises: following a predetermined sequenceof multiplier values.

In Example 11, the subject matter of any one or more of Examples 1-10optionally include that assigning a multiplier value based on the countof preceding stacked reels comprises: selecting a lookup table of aplurality of lookup tables based on the count of preceding stackedreels; and randomly selecting, using a random number generator and thelookup table, a random multiplier value.

In Example 12, the subject matter of any one or more of Examples 1-11optionally include that determining outcomes for at least one subsequentreel, further comprises: assigning a first multiplier value to a firststacked reel; assigning a second multiplier value to a second stackedreel, wherein the first stacked reel is adjacent to and precedes thesecond stacked reel; and assigning a third multiplier value to a thirdstacked reel, wherein the second stacked reel is adjacent to andprecedes the third stacked reel.

In Example 13, the subject matter of Example 12 optionally includes thatthe instructions further cause the game controller to control thedisplay system to: merge the first and second multiplier values todisplay a first merged multiplier value equal to the product of thefirst and second multiplier values; and merge the first mergedmultiplier value and the third multiplier value to display a secondmerged multiplier value equal to the product of the first, second, andthird adjacent multiplier values.

In Example 14, the subject matter of Example 13 optionally includes thatthe instructions further cause the game controller to: assign a fourthmultiplier value to a fourth stacked reel, wherein the third stackedreel is adjacent to and precedes the fourth stacked reel; and controlthe display system to merge the second merged multiplier and the fourthmultiplier value to display a third merged multiplier value equal to theproduct of the first, second, third, and fourth adjacent multipliervalues.

In Example 15, the subject matter of any one or more of Examples 12-14optionally include that the instructions further cause the controllerto: control the display system to merge the first, second, and thirdmultiplier value to display a merged multiplier value equal to theproduct of the first, second, and third adjacent multiplier values.

Example 16 is a gaming system, comprising: a user interface systemconfigured for receiving an indication to initiate one or more instancesof a slot game; a display system comprising one or more displays; and acontrol system comprising one or more processors, wherein the controlsystem executes instructions which cause the control system to performoperations comprising: randomly selecting, with a random numbergenerator, display symbols for a first reel, the display symbolsselected from a first symbol set including one or more special symbols;randomly selecting, with a random number generator, display symbols fora second reel, the display symbols selected from a second symbol setincluding a plurality of special symbols; randomly selecting, with arandom number generator, display symbols for a third reel, the displaysymbols selected from a third symbol set including a plurality ofspecial symbols; if the second reel is a stacked reel, such that therandomly selected display symbols form a stack of special symbols, andpart of a win combination, assigning a first multiplier value to thesecond reel based on the second reel being the first stacked reel; ifthe third reel is a stacked reel and part of a win combination,assigning a second multiplier value to the third reel based on the thirdreel being the second stacked reel; controlling the display system todisplay outcomes of the first, second, and third reels; and for eachstacked reel, controlling the display system to display the assignedmultiplier value over the corresponding reel.

In Example 17, the subject matter of Example 16 optionally includes thatexecuting the instructions cause the control system to performoperations further comprising: for each stacked reel, controlling thedisplay system to replace the stack of special symbols with a singlesymbol.

In Example 18, the subject matter of any one or more of Examples 16-17optionally include for adjacent stacked reels, controlling the displaysystem to replace assigned multiplier values of the adjacent stackedreels with a merged multiplier value representing a product of theassigned multiplier values of the adjacent stacked reels.

Example 19 is one or more machine-readable devices storing instructions,wherein the instructions when executed by one or more processors, causeperformance of operations, comprising: randomly determining, using arandom number generator, an outcome for each reel of a plurality ofreels, each outcome including display symbols selected from a reel stripthat includes a plurality of special symbols; determining that theoutcome of at least one reel of the plurality of reels includes a stackof special symbols, such that the at least one reel is a stacked reel;and if the stacked reel is part of a win combination, assigning amultiplier value to the stacked reel using a stack counter and a lookuptable, such that the assigned multiplier value is based on the number ofpreceding stacked reels.

In Example 20, the subject matter of Example 19 optionally includes thatthe at least one reel comprises two adjacent reels that are part of awin combination, such that each of the two adjacent reels is assigned amultiplier value, the product of which is used as a merged multiplier.

While the disclosure has been described with respect to the figures, itwill be appreciated that many modifications and changes may be made bythose skilled in the art without departing from the spirit of thedisclosure. Any variation and derivation from the above description andfigures are included in the scope of the present disclosure as definedby the claims.

What is claimed is:
 1. A non-transitory computer readable mediumcomprising computer readable code executable by one or more processorsto: generate first display symbols for a first reel of a set of reelsfrom a first set of symbols having one or more special symbols; generatesecond display symbols for a second reel of the set of reels from asecond set of symbols having plurality of special symbols; and inaccordance with the second display symbols comprising a first stack ofspecial symbols: assign a first multiplier value to the second reel, andcontrol a display system to display the first multiplier value inassociation with the first reel.
 2. The non-transitory computer readablemedium of claim 1, further comprising computer readable code to:generate a random number generator outcome for each reel of the set ofreels using a random number generator; and determine an outcome based onthe random number generator outcome for each reel of the set of reels,the first display symbols, the second display symbols, and the firstmultiplier value.
 3. The non-transitory computer readable medium ofclaim 1, wherein the computer readable code to control the displaysystem to display the first multiplier value in association with thefirst reel comprises computer readable code to: control the displaysystem to replace the second display symbols with a single symbol. 4.The non-transitory computer readable medium of claim 1, furthercomprising computer readable code to: generate third display symbols fora third reel of the set of reels from a third set of symbols havingfewer special symbols than the second set of symbols; and in accordancewith the third display symbols comprising a second stack of specialsymbols, assign a second multiplier value to the second reel.
 5. Thenon-transitory computer readable medium of claim 4, further comprisingcomputer readable code to: control the display system to replace thethird display symbols with a single symbol.
 6. The non-transitorycomputer readable medium of claim 4, further comprising computerreadable code to: in accordance with second reel and third reel beingadjacent reels among the set of reels, determine a product of the firstmultiplier value and the second multiplier value as a merged multiplier;assign the merged multiplier value to the second reel and the thirdreel; and control the display system to present the merged multipliervalue in accordance with the second reel and the third reel.
 7. Thenon-transitory computer readable medium of claim 1, wherein the computerreadable code to assign a first multiplier value to the second reelcomprises computer readable code to: determine the first multipliervalue using a stack counter and a lookup table, such that the assignedmultiplier value is based on a number of preceding stacked reels.
 8. Agaming system, comprising: a display system comprising one or moredisplays; and a control system comprising one or more processors,wherein the control system executes computer readable code which causethe control system to: generate first display symbols for a first reelof a set of reels from a first set of symbols having one or more specialsymbols; generate second display symbols for a second reel of the set ofreels from a second set of symbols having plurality of special symbols;and in accordance with the second display symbols comprising a firststack of special symbols: assign a first multiplier value to the secondreel, and control the display system to display the first multipliervalue in association with the first reel.
 9. The gaming system of claim8, wherein the control system further executes computer readable codewhich cause the control system to: generate a random number generatoroutcome for each reel of the set of reels using a random numbergenerator; and determine an outcome based on the random number generatoroutcome for each reel of the set of reels, the first display symbols,the second display symbols, and the first multiplier value.
 10. Thegaming system of claim 8, wherein the computer readable code to controlthe display system to display the first multiplier value in associationwith the first reel comprises computer readable code to: control thedisplay system to replace the second display symbols with a singlesymbol.
 11. The gaming system of claim 8, wherein the control systemfurther executes computer readable code which cause the control systemto: generate third display symbols for a third reel of the set of reelsfrom a third set of symbols having fewer special symbols than the secondset of symbols; and in accordance with the third display symbolscomprising a second stack of special symbols, assign a second multipliervalue to the second reel.
 12. The gaming system of claim 11, wherein thecontrol system further executes computer readable code which cause thecontrol system to: control the display system to replace the thirddisplay symbols with a single symbol.
 13. The gaming system of claim 11,wherein the control system further executes computer readable code whichcause the control system to: in accordance with second reel and thirdreel being adjacent reels among the set of reels, determine a product ofthe first multiplier value and the second multiplier value as a mergedmultiplier; assign the merged multiplier value to the second reel andthe third reel; and control the display system to present the mergedmultiplier value in accordance with the second reel and the third reel.14. The gaming system of claim 11, wherein the computer readable code toassign a first multiplier value to the second reel comprises computerreadable code to: determine the first multiplier value using a stackcounter and a lookup table, such that the assigned multiplier value isbased on a number of preceding stacked reels.
 15. A method implementedby at least one processor in communication with at least one memory, themethod comprising: generating first display symbols for a first reel ofa set of reels from a first set of symbols having one or more specialsymbols; generating second display symbols for a second reel of the setof reels from a second set of symbols having plurality of specialsymbols; and in accordance with the second display symbols comprising afirst stack of special symbols: assigning a first multiplier value tothe second reel, and controlling a display system to display the firstmultiplier value in association with the first reel.
 16. The method ofclaim 15, further comprising: determining an outcome based on the firstdisplay symbols, second display symbols, and the first multiplier value.17. The method of claim 15, wherein controlling the display system todisplay the first multiplier value in association with the first reelcomprises: controlling the display system to replace the second displaysymbols with a single symbol.
 18. The method of claim 15, furthercomprising: generating third display symbols for a third reel of the setof reels from a third set of symbols having fewer special symbols thanthe second set of symbols; and in accordance with the third displaysymbols comprising a second stack of special symbols, assigning a secondmultiplier value to the second reel.
 19. The method of claim 18, furthercomprising: controlling the display system to replace the third displaysymbols with a single symbol.
 20. The method of claim 18, furthercomprising: in accordance with second reel and third reel being adjacentreels among the set of reels, determining a product of the firstmultiplier value and the second multiplier value as a merged multiplier;assigning the merged multiplier value to the second reel and the thirdreel; and controlling the display system to present the mergedmultiplier value in accordance with the second reel and the third reel.